1. Field of the Invention
This invention relates to organic chemistry and more particularly it relates to a novel hexapeptide and a novel medicinal preparation to treat erosive and ulcerative lesions of the gastrointestinal tract, based thereon.
2. Prior Art
Antagonists to histamine H.sub.2 receptors, e.g. cimetidine, (Somerville K. M., Langman, M. J. S. "Drugs", 1983, 24, p. 315-330) are now widely used (per os) to treat exacerbations of gastric and duodenal ulcer. Said preparations is given as tablets for several months. Short courses of cimetidine therapy usually provoke relapses of peptic ulcer. Administration of cimetidine produces some side effects, such as diarrhea, myalgia, allergic reactions, depressions, gynaecomasty due to hypersecretion of prolactin, inhibition of the intrinsic factor secretion and of vitamin B.sub.12 absorption, and impairment of the excretory hepatic function. For these consideration cimetidine is not recommended for treatment of patients with hepatic and renal failure and some other diseases.
Patients with ulcerative colitis are now mainly treated with sulfasalazine (a mixture of 5-aminosalicylate and sulfapyridine). It is given orally, but is poorly tolerated by patients, producing side effects such as nausea, vomiting, headache, allergic response and leucopenia ("Inflammatory Bowel Diseases", ed. by R. N. Allan, Edinburg, 1983).
A hexapeptide having the formula Tyr-D-Ala-Gly-Phe-Leu-Arg is known in the prior art. Its structure is similar to that of the proposed new hexapeptide (U.S. Pat. No. 4,565,005), and the preparation is used to treat duodenal ulcer. But the preparation is effective only when given parenterally, while its efficacy with administration per os is low.